Pilot 5 will use psychophysiological recording techniques as well as classical conditioning theory and methodology to assess learning and memory in patients with Alzheimer's disease (AD). Because AD is accompanied by progressive deterioration in verbal and motor performance, standard neuropsychological methods alone may not be adequate to assess completely the residual cognitive abilities of patients with advanced disease. We will measure facial recognition memory, which is thought to be impaired in patients with AD, by recording their autonomic reactivity to slides of known (famous) faces. Such implicit memory has been detected in previous studies in which verbal recognition was not evident. Skin conductance and heart rate responses of individuals with aD with varying levels of impairment will be measured during randomized computer- controlled slide presentations of known persons, unknown persons, and blanks. Verbal recognition and self-controlled slide viewing durations (timed in millisecond accuracy) will also be obtained and correlated with measures of autonomic reactivity. Controls will be nondemented subjects matched for age and sex. In these same individuals, we will measure autonomic an motor associative learning through the use of classical conditioning. The development of heart rate and eyeblink conditioned responses will be recorded during trials in which an auditory conditioned stimulus (tone) one_second duration is followed and overlapped during the final 500 milliseconds by a light-flash, unconditioned stimulus. The outcomes of these two studies are likely to provide standardized assessment techniques that may be used to assess changes in performance during progression of disease.